Methods for forming capacitor structures; and methods for removal of organic materials

ABSTRACT

The invention includes methods of forming capacitor structures and removing organic material. An organic material, such as a photoresist, is disposed on a substrate. The organic material is contacted with a chemical mechanical polishing pad and a polishing fluid to remove the organic material from the substrate. The polishing fluid can be essentially free of particles, and can be water.

TECHNICAL FIELD

[0001] The present invention relates generally to semiconductorprocessing. In particular applications the invention pertains to methodsof forming capacitor structures and methods of resist removal.

BACKGROUND

[0002] Increased performance, both with regard to more complexfunctionality and higher speeds, is a continuing goal of efforts inadvancing the semiconductor arts. One method that has been used forachieving this goal is scaling downward the size of individual devicesused in forming advanced semiconductor integrated circuits. However, itis found that at times, changes in the components used in fabricatingsuch down-sized devices are advantageous. For example, where capacitors,such as those used in memory integrated circuits, are scaled downward insize, dielectric materials such as silicon oxide and silicon nitride areoften replaced with alternate materials having a higher dielectricconstant to achieve desired capacitance. Where such replacements ofdielectric materials are made, it can be advantageous to form capacitorelectrodes comprising one or more of platinum, tantalum, ruthenium,iridium, and titanium. Such electrodes can comprise, for example, alloysof various metals and/or nitrides of various metals, including, forexample, titanium nitride. The capacitors comprising metallic electrodesare well known in the art, and are frequently described asmetal-insulator-metal capacitor constructions.

[0003] One method for patterning various dielectric and conductivematerials is chemical mechanical polishing (CMP). A material (such asplatinum), can be blanket formed within an opening and over surfacesproximate the opening. The material can be removed from over thesurfaces by a CMP method. The material within the opening, elevationallybelow that upper surface, will not be removed. The material within theopening can ultimately form a capacitor electrode structure. A problemwith the CMP method can be scratching or smearing of the material, whichcan prevent the proper forming of the ultimately desired capacitorstructure. For instance, if the material is platinum or an alloy ofplatinum, scratching or smearing of the platinum can occur in a CMPprocess. It can be difficult, and for all practical purposes impossible,to remove smeared platinum from within a container.

[0004] It would be desirable, to develop a CMP method where the removalof portions of various materials (such as platinum or barrier materials)can be effected without scratching or smearing across surfaces of thematerials. It would also be desirable if such a CMP method wascost-effective and could be performed using essentially standard CMPprocessing tools.

SUMMARY

[0005] In one aspect, the present invention can provide methods forforming structures (such as capacitor or plug structures) and/orremoving resist from a semiconductor substrate. A material is formedover a substrate, and a resist layer is formed over the material.Subsequently, at least a portion of the resist layer is removed toexpose a desired portion of the material. The resist layer can beremoved by providing contact of a chemical mechanical polishing pad anda polishing fluid with the resist layer. Such contact can be provided bya chemical mechanical polishing system that encompasses a mechanism formoving the polishing pad and/or the substrate. In some embodiments ofthe present invention it is advantageous to provide that the polishingfluid has a particle concentration of less than or equal to about 0.1%by weight of a silica-comprising material, and in particular embodimentsit is advantageous for the polishing fluid to be essentially free ofparticles. In particular aspects, the polishing fluid can comprisetetramethylammonium hydroxide (TMAH) or ammonia to increase a rate ofremoval of various compositions by the fluid.

[0006] Some embodiments of the present invention provide for forming arecess within the semiconductor substrate prior to forming the materialthat is to be covered by the resist. For such embodiments, the materialcan be formed to partially fill the recess and extend outward over anupper surface of the semiconductor substrate. The resist layer can beformed within the partially filled recess.

[0007] A suitable semiconductor substrate can encompasses asemiconductive portion and an overlying insulative portion. Forembodiments that encompass a recess, such recess can be formed withinthe insulative portion. In some embodiments the recess extends toexpose, at a bottom and/or sidewalls of the recess, a portion of thesemiconductive portion or a portion of a conductive device formed overor in the semiconductive portion. Where the material encompasses aconductive material, electrical communication between the conductivematerial and the semiconductive portion or conductive device can beprovided through the bottom or sidewalls of the recess. In someembodiments of the present invention, the material can include more thanone layer. For example, the material can encompass a first layer of afirst composition and a second layer of a second composition overlyingthe first layer. The two compositions can be, for example, a firstcomposition comprising metal and both of nitrogen and silicon (such asTaSiN); and a second composition consisting essentially of metal andnitrogen (such as TaN).

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Preferred embodiments of the invention are described below withreference to the following accompanying drawings.

[0009]FIG. 1 is a diagrammatic, cross-sectional, fragmentary view of aconstruction at a preliminary stage of an exemplary semiconductorfabrication process.

[0010]FIG. 2 is a view of the FIG. 1 construction at a processing stagesubsequent to that of FIG. 1.

[0011]FIG. 3 is a view of the FIG. 1 construction at a processing stagesubsequent to that of FIG. 2.

[0012]FIG. 4 is a diagrammatic, cross-sectional, fragmentary view of aconstruction at a preliminary stage of a fabrication process of forminga barrier layer.

[0013]FIG. 5 is a cross-sectional representation of a portion of asemiconductor substrate at an early process stage of an exemplaryembodiment of the present invention.

[0014]FIG. 6 is a cross-sectional representation of the portion of asemiconductor substrate depicted in FIG. 5 at a subsequent process stageof an exemplary embodiment of the present invention.

[0015]FIG. 7 is a cross-sectional representation of the portion of asemiconductor substrate depicted in FIG. 6 at a subsequent process stageof an exemplary embodiment of the present invention.

[0016]FIG. 8 is a cross-sectional representation of the portion of asemiconductor substrate depicted in FIG. 7 at a subsequent process stageof an exemplary embodiment of the present invention.

[0017]FIGS. 9A and 9B are cross-sectional representations of the portionof a semiconductor substrate depicted in FIG. 8 at alternate subsequentprocess stages of exemplary embodiments of the present invention.

[0018]FIG. 10 is a cross-sectional representation of the portion of asemiconductor substrate depicted in FIG. 9A at a subsequent processstage of an exemplary embodiment of the present invention.

[0019]FIG. 11 is a cross-sectional representation of an integratedcapacitor structure formed employing methods of exemplary embodiments ofthe present invention.

DETAILED DESCRIPTION

[0020] This disclosure of the invention is submitted in furtherance ofthe constitutional purposes of the U.S. Patent Laws “to promote theprogress of science and useful arts” (Article 1, Section 8).

[0021] The present invention can encompass methods of polishing resistto remove the resist from over conductive materials. An exemplaryembodiment of the present invention is described with reference to FIGS.1-3.

[0022] Referring to FIG. 1, a construction 100 comprises a mass 102having an opening 104 extending therein. Mass 102 can comprise aninsulative material such as, for example, borophosphosilicate glass(BPSG) and/or silicon dioxide deposited from TEOS, and can be supportedby a semiconductor substrate (not shown). To aid in interpretation ofthe description of the illustrations and claims that follow, the term“semiconductor substrate” is defined to mean any constructionencompassing silicon semiconductive material, including, but not limitedto, bulk silicon semiconductive materials such as a siliconsemiconductor wafer (either alone or in assemblies encompassing othermaterials thereon) and silicon semiconductive material layers (eitheralone or in assemblies encompassing other materials). The term“substrate” refers to any supporting structure, including, but notlimited to, the semiconductor substrates described above.

[0023] A metal-containing layer 106 extends over mass 102 and withinopening 104. Layer 106 can consist essentially of, for example, platinumor a platinum-containing alloy. A layer 108 is formed over layer 106.Layer 108 can comprise, for example, photoresist, and fills opening 104.

[0024] Referring to FIG. 2, layer 108 is polished from over layer 106 toexpose portions of layer 106 proximate opening 104. The layer 108 isnot, however, removed from within opening 104. The polishing of layer108 preferably utilizes a polishing pad in combination with a solutionsubstantially lacking in particulates. Accordingly, in particularaspects of the invention, the polishing of layer 108 occurs throughmechanical action of the pad alone. The polishing proceeds through layer108, but stops on layer 106. The polishing can be accomplished withlittle, if any, smearing or scratching of layer 106. It is noted that insome aspects of the invention the polishing solution can consistessentially of water, and in other aspects the polishing solution cancomprise a combination of chemicals. For instance, the solution cancomprise a combination of water and a base (such as, for example, TMAH),so that the solution has a basic pH.

[0025] Referring to FIG. 3, the exposed portions of layer 106 areremoved with a dry etch. In subsequent processing (not shown), resist108 can be removed from within opening 104 by, for example, ashing.

[0026] A process similar to that described with reference to FIGS. 1-3can be utilized for etching of various so-called barrier layers. Barrierlayers are provided, for example, to alleviate diffusion of Si and O atelevated temperatures, and can be incorporated into various capacitorstructures. An exemplary material which can be utilized as a barrierlayer is TaSi_(x)N_(y) (which can also be referred to herein as TaSiN,with the Ta, Si and N of the representation “TaSiN” referring to theelements contained within the designated compound and not to anyparticular stoichiometric relationship of the elements).

[0027] A barrier layer fabrication process is described with referenceto FIG. 4. Specifically, FIG. 4 shows a construction 120 comprising amass 122 having an opening 124 extending therein. Mass 122 can comprisean insulative material such as, for example, silicon dioxide, and can besupported by a semiconductor substrate (not shown). A barrier layer 126extends over mass 122 and within opening 124. Layer 126 can comprise,for example, TaSi_(x)N_(y). A layer 128 is formed over layer 126. Layer128 can comprise, for example, photoresist, and fills opening 124.

[0028] Ultimately, the barrier layer material 126 is to be removed fromover an uppermost surface of mass 122, but left within opening 124. Suchcan be accomplished with processing analogous to that discussed abovewith reference to FIGS. 1-3.

[0029]FIG. 5 depicts a cross-sectional representation of a portion of asemiconductor substrate 10 having an insulative portion 14 disposed overa semiconductive substrate 12. Insulative portion 14 can encompass oneor more layers of a variety of exemplary materials such as, for example,silicon oxide, silicon nitride and silicon oxynitride. In particularembodiments of the present invention, portion 14 encompasses a BPSG(BoroPhosphoSilicate Glass) material or a TEOS-deposited silicondioxide. Semiconductive portion 12 can encompass a single crystalsilicon material.

[0030] Referring to FIG. 6, structure 10 is illustrated after a recess20 is formed within portion 14. Recess 20 is typically formed by apatterning process that encompasses a masking step and an etching step.Recess 20 has a bottom 22 and sidewalls 24. As depicted, bottom 22 iselevationally at an upper surface 16 of semiconductive substrate 12.However, such is illustrative only and it will be understood that insome embodiments of the present invention bottom 22 is elevationallyabove and displaced from upper surface 16. For example, in someembodiments, bottom 22 can be at an upper surface of an integratedcircuit device such as a conductive line disposed on semiconductivesubstrate 12 (not shown). After forming recess 20, a layer of material30 is formed over substrate 10. Material 30 is within recess 20 andextends laterally outward from recess 20 over insulative portion 14.More specifically, material 30 is over bottom 22 and sidewalls 24 ofrecess 20, only partially filling recess 20.

[0031] Material 30 can encompass conductive materials such as platinum(Pt), iridium (Ir), ruthenium (Ru), tantalum (Ta), titanium (Ti) andmixtures or alloys of such materials. In addition, or alternatively,material 30 can encompass oxides, nitrides and suicides of variousmetals. For example, in some embodiments in accordance with the presentinvention, material 30 encompasses one or more of a platinum-rutheniumalloy, ruthenium oxide (RuO), tantalum silicon nitride (TaSiN) orruthenium silicide (RuSi). In addition, it will be understood that forsome embodiments of the present invention, material 30 is formed of morethan one layer. In one exemplary embodiment of the present invention, abarrier layer (not shown) such as a tantalum silicon nitride (TaSiN)material is first formed over insulative portion 14 and within recess 20and a second layer of electrode material (not shown) such as tantalumnitride (TaN) is second formed over the barrier layer and within recess20.

[0032] In particular aspects of the invention, material 30 can comprisesa tantalum-containing mass. Such mass can include one or both of siliconand nitrogen in addition to the tantalum.

[0033] Referring to FIG. 7, a layer 40 comprising, consistingessentially of or consisting of, an organic material (such as an organicpolymer), is depicted over substrate 10. Specifically, layer 40 isformed over material 30 and fills recess 20. Layer 40 can, in particularapplications, comprise, consist essentially of, or consist of, aphotoresist material. For example, layer 40 can comprise an exemplaryphotoresist material designated OiR 897 10i™ and manufactured by ArchMicroelectronics, of Norwalk, Conn. Additionally, or alternatively,layer 40 can comprise resist compositions formed without aphotosensitive component (non-photosensitive resists) and/or polyimidematerials.

[0034] Resist or organic material layer 40 can be formed using any ofseveral appropriate process methods, for example by spin coating,spraying or dip-coating. In this manner a generally uniform layer 40 isprovided that advantageously fills recess 20 (FIG. 6) as depicted. Afterlayer 40 is formed, it can be subjected to what is commonly referred toas a “hard” bake. The specific processing conditions for the applicationand baking of the material used to form resist layer 40 will beunderstood, by one of ordinary skill in the semiconductor arts, todepend on the specific material employed for resist layer 40. Thus wherethe exemplary OiR 897 10i™ material is used, it has been foundadvantageous to apply such material by a spin-coating process and tosubsequently hard bake the layer at a temperature of from about 85degrees Celsius (° C.) to about 100° C. for a period of time fromseveral tens of seconds to several minutes in duration.

[0035] Referring to FIG. 8, the structure of FIG. 7 is depicted after aportion of resist layer 40 is removed. As shown, resist layer 40 isremoved such that segments 34 of material 30 outward of and adjacent torecess 20 are exposed and a resist plug 42 within recess 20 is formed.Layer 40 has thus been removed selectively relative to material 30.

[0036] The removal of the portion of resist or organic material layer 40can be accomplished by providing contact of a chemical mechanicalpolishing pad and a polishing fluid (not shown) with resist layer 40.The term “chemical mechanical polishing (CMP) pad” refers to aconstruction traditionally employed for performing chemical mechanicalpolishing. Such constructions can include pads used in a system forchemical mechanical polishing where the CMP pad is provided to have atleast one of rotational motion about an axis and linear motion along anaxis. CMP pads utilized with embodiments of the present invention canencompass a polyurethane material and are manufactured by, for example,Rodel Products of Phoenix, Ariz. and Thomas West, Inc. of Sunnyvale,Calif. Chemical mechanical polishing systems that provide the at leastone of linear motion and rotational motion include, for example, theTERES™ CMP System manufactured by LAM Research Corporation of Fremont,Calif. and the MIRRA MESA ADVANCED INTEGRATED CMP SYSTEM™ manufacturedby Applied Materials, Inc., of Santa Clara, Calif., respectively.Exemplary pads are those formed of a rigid or semi-rigid microporouspolyurethane material, or polyurethane-impregnated polyester material ora combination of such materials, although other appropriate materialscan be used. The specific pad employed will depend, in part, on thespecific resist material employed and the conditions at which theselected resist material was processed to form layer 40. It is notedthat harder pads can induce a faster CMP removal rate of resist thansofter pads through increased mechanical action. However, the harderpads may also create more scratches than softer pads to an underlyingmaterial 34. Accordingly, the physical characteristics of a polishingpad can be chosen to balance a desired removal rate with an acceptablelevel of scratching in material 34.

[0037] In addition to the pad characteristics, the nature of thepolishing fluid employed in contact with both the CMP pad and resistlayer 40 can be a factor in determining an advantageous CMP pad materialand/or construction. Accordingly, it can be desired to adjust a pH ofthe polishing fluid to a desired range. In particular applications, TMAHcan be utilized in a polishing solution when a basic pH is desired.

[0038] Chemical mechanical polishing is known in the art to be suitablefor removing a wide variety of materials. Typically such materials arehard materials such as silicon oxide, silicon nitride, polycrystallinesilicon and the like. While the polyurethane material typically employedto form CMP pads has some degree of roughness, material removal effectedby such pads is believed the result, in significant part, of abrasiveparticles that are typically included into the polishing fluid or slurryand not the pad itself. In addition, the polishing fluid typicallyencompasses a material that is chemically reactive with regard to thematerials being polished and thus is also generally significant in theremoval of a material. Thus CMP is the combined action of (1) thechemical reactivity between the fluid and the materials being polishedor removed, (2) the abrasiveness of the included particles, and (3) theeffect of the CMP pad to create a pressure of contact and a linearvelocity, in excess of zero, of that contact through which (1) and (2)can interact with the material being polished and/or removed.

[0039] Embodiments of the present invention, however, can employ apolishing fluid that is selected to be essentially unreactive with bothresist or organic material layer 40 and conductive material layer 30. Inaddition, such fluid is typically provided having few, if any,particles. Exemplary materials for such a polishing fluid include, waterhaving essentially no particles, or an aqueous based polishing fluidhaving silica-comprising particles where the concentration of suchparticles is less than or equal to 0.1% by weight. Thus absent thechemical reactivity and the abrasiveness of included particles, it istheorized that the principle mechanism for the removal of resist layer40 is the abrasiveness of the CMP pad and the pressure with which suchpad contacts layer 40. Advantageously, it is found that where such apolishing fluid and CMP pad are used for removing resist layer 40 toexpose substantially all of upper surfaces 32 of material 30, theabsence of particles in the polishing fluid and the generally unreactivenature of the polishing fluid itself, provide that upper surfaces 32 areessentially unpolished. That is to say that exposed portions 34 ofmaterial 30 act essentially as an etch or polish stop layer and resistremoval is essentially stopped with the forming of resist plug 42. Itwill be understood, as the polishing fluid employed by embodiments ofthe present invention use little or no particulates in the polishingfluid, that when resist layer 40 is removed to expose upper surface 32,there is little or no removal of such material. Thus scratches and/orsmears are essentially or entirely eliminated.

[0040] It is noted that particles can be generated during polishing of aresist, with the particles corresponding to removed fragments of theresist. In particular applications of the invention, a total amount ofparticles within a fluid utilized for removing resist, other thanparticles generated from the removal of the resist, is less than orequal to 0.1%, by weight, of a polishing fluid. In some embodiments thenumber of particles in the fluid, other than particles generated fromresist removal, is 0%, or in other words, non-detectable.

[0041] In particular aspects of the invention, chemical reactivity of apolishing fluid can be enhanced by, for example, shifting a pH of thepolishing fluid. Such can be accomplished by, for example, incorporatingone or both of ammonia and TMAH within the polishing fluid. Preferably,the increase in chemical reactivity of the polishing fluid will berelative to mass 40 (FIG. 7) and not material 30. Accordingly, removalof mass 40 relative to material 30 will be further enhanced by theadditional chemical reactivity of the polishing fluid. In applicationsin which material 30 comprises platinum and mass 40 comprisesphotoresist, it can be desirable to include one or both of ammonia andTMAH in the polishing fluid to obtain a pH of the polishing fluid offrom about 8 to about 12.

[0042] While various organic materials are appropriate for formingresist layer 40, and while various polishing fluids, CMP pad materialsand the like can be selected for removing layer 40 from over material 30adjacent recess 20 to form the structure depicted in FIG. 4, it has beenfound advantageous where an OiR 897 10i™ resist is selected and formedemploying a hard bake step at a temperature of about 92° C. for about 60seconds, to use a Rodel IC1000™ or 1400 CMP™ pad, or Sycamore OXP™ pad,and a polishing fluid having an initial particulate concentration ofless than or equal to 0.1% by weight for the removal. As one of skill inthe semiconductor arts will understand, where other materials andprocess conditions are employed for forming resist layer 40 (FIG. 3),tailoring CMP processing conditions to form plug 42 and to exposeportions 34 of material 30 is made possible by this disclosure.

[0043] In some embodiments of the present invention, an apparatus todetermine a resist removal endpoint is employed. For example, the torquerequired to provide motion of the CMP pad with respect to the substratewill vary when material 30 becomes substantially exposed, that is tosay, when essentially all of the resist layer is removed from over uppersurfaces 32 of material 30. Thus an apparatus for monitoring changes intorque can be effective for determining the endpoint. Other methods anddevices for determining endpoint are also possible. For example, asmaterial 30 becomes exposed, the reflectivity of substrate 10 willchange. Thus an apparatus for monitoring reflectivity can also beeffective for determining the endpoint of the resist removal.

[0044] Referring to FIG. 9A, the structure of FIG. 8 is shown at onealternate, subsequent processing stage. The exposed portions 34 of layer30 (FIG. 8) are removed defining a portion 36 a of layer 30 withinrecess 20 as well as an essentially planar upper surface 16 a ofsemiconductor substrate 10 laterally adjacent recess 20. Exposedportions 34 can be removed employing a chemical mechanical polishingmethod where a second polishing fluid or slurry is provided, replacingthe polishing fluid used for removing the resist, once the structure ofFIG. 8 is formed. In other embodiments, both the polishing fluid and CMPpad are changed. It will be understood that such changes of thepolishing fluid and/or the CMP pad can be effected at a single polishingstation or by moving substrate 10 to an alternate station, where suchalternate station has the changed material(s).

[0045] Second polishing fluid, and where employed a second CMP pad, areselected to provide effective removal of exposed portions of layer 34(FIG. 8). Thus the second fluid is different from the first fluid inthat it typically has an increased initial concentration of particlesand will typically be chemically reactive to the conductive material oflayer 34. Where a second CMP pad is used, such second pad is compatiblewith the second fluid. In addition, the second fluid will typically havean enhanced reactivity toward the material of exposed portions 34 beingremoved, as compared to the first fluid's general absence of reactivityto the material of exposed portions 34.

[0046] It will be noted while the CMP processing used to remove exposedportions 34 can also remove some of resist plug 42 a, such plugadvantageously serves to protect recess 20. That is to say, if theremoval of exposed portions 34 (FIG. 8) during a CMP process results inscratches or smearing of the material of portions 34, resist plug 42 aprevents such scratches and smears from effecting the structure formedwithin recess 20. In other words, resist plug 42 a can prevent theremoved material of exposed portions 34 from entering recess 20 duringCMP removal of such exposed portions and coming in contact with or beingproximate to portions 36 a.

[0047] In a particular aspect of the invention the processing of FIGS.5-9A is utilized in formation of a material 34 comprising TaSiN and/orTaN (with the materials being described in terms of the atoms comprisedby the materials rather than any particular stoichiometry). The polishutilized to remove resist 40 between the stage of FIG. 7 and that ofFIG. 8 is a first polish comprising substantially no particles in thepolishing fluid. The polish utilized to remove material 30 in proceedingfrom the stage of FIG. 8 to that of FIG. 9A is a second polish utilizingparticles. An exemplary polish for proceeding from the stage of FIG. 8to that of FIG. 9A utilizes a polishing slurry comprising a materialavailable from Hitachi as T605™, together with from about 0.1 wt % toabout 0.5 wt % H₂O₂. The polishing of resist 40 thus utilizes a solutiontailored to remove resist 40, and the polishing of material 30 utilizesa solution tailored to remove material 30. Accordingly, the removal ofeach of materials 40 and 30 can proceed with high uniformity. In someaspects of the invention, better uniformity can be obtained by utilizingthe two tailored etching solutions than by using a single etchingsolutions to remove both of materials 40 and 30 in proceeding from thestage of FIG. 7 to that of FIG. 9A.

[0048]FIG. 9B depicts an alternate embodiment where exposed portions 34(FIG. 8) are removed using a chemical or a plasma etching method. Asdepicted, a raised plug 42 b is seen to extend upward from surface 16 bof substrate 10. Thus subsequent to the forming of resist plug 42 andexposed portions 34 (FIG. 8), substrate 10 is either exposed to achemical solution or plasma that removes the material of such exposedportions. Such chemical solution or plasma is selected to be essentiallyunreactive with respect to the resist material and thus a raised plug 42b is formed. Analogous to what was seen for the structure of FIG. 9A,plug 42 b serves to protect portion 36 b within recess 20.

[0049] Referring to FIG. 10, a structure is illustrated subsequent tothe processing of FIGS. 9A or 9A, and specifically, subsequent to theremoval of resist plugs 42 a or 42 b. Plugs 42 a or 42 b can be removedby employing a chemical solution or plasma tailored to remove thematerial of the plugs. Where plugs 42 a and/or 42 b are a photoresistmaterial, one exemplary removal method is an oxygen plasma, although anyappropriate method can be used. As seen, material layer 30 istransformed into layer 36 entirely within recess 20 and adjacent bottom22 and sidewalls 24 of such recess 20. Layer 36 can be, for example, anelectrode of a capacitor structure, some or all of which to be formedwithin recess 20. Advantageously, the structure depicted in FIG. 10 hasbeen formed without a photomasking step subsequent to the forming ofrecess 20. Rather, as shown above, the patterning to form layer 36within recess 20 can be accomplished, in some embodiments, usingessentially blanket depositions and CMP processing only. In otherembodiments, chemical or plasma processing can be used, after theforming of plug 42 (FIG. 8), to define layer 36 as discussed above, alsowithout the need for a photomasking step.

[0050] Referring to FIG. 11, a portion of a semiconductor substrate 10 aencompassing a semiconductive portion 12 a and overlying insulativeportions 15 is depicted. A portion of a capacitor structure 70, inaccordance with embodiments of the present invention, is shown disposedwithin an upper, second formed portion of insulative layers 15.

[0051] Within semiconductive portion 12 a is a conductive node 64,disposed laterally between and elevationally below conductive linestructures 62. Conductive plug 60 is depicted disposed above and inelectrical communication with conductive node 64. Where conductive plug60 encompasses a doped polysilicon material, generally a contactenhancement material layer 55 encompassing a metal silicide (such astitanium silicide) is disposed over and in electrical communication withthe polysilicon of conductive plug 60.

[0052] Turning to capacitor structure 70, disposed within an upper orsecond formed part of insulative portion 15, such encompasses recess 20having a material layer 36 c formed therein. Recess 20 being formed in amanner analogous to the methods previously discussed with regard to FIG.6, and material layer 36 c being formed and subsequently defined in amanner analogous to the defining of layer 36 from layer 30 in FIGS. 9Aor 9B. Material layer 36 c, however, encompasses a diffusion barriermaterial and can be formed of a single such diffusion barrier material,or alternatively of such a barrier material and a conductive material,such as described previously for layer 30. Exemplary diffusion barriermaterials include, among others, tantalum nitride and/or tantalumsilicon nitride, while exemplary conductive materials include, amongothers, materials comprising Pt, Ru, Ta and mixtures or alloys thereof.It will be understood that while exemplary materials for layer 36 c areprovided, other barrier materials and/or combinations of barriermaterials and conductive materials other can also be employed. Any andall of such materials can be formed by appropriate methods such aschemical vapor deposition of physical vapor deposition methods.

[0053] Typically where capacitor structure 70 employs a high dielectricconstant material layer 50, barrier layer material is provided withinlayer 36 c to reduce and/or eliminate any reactive interactions, forexample between such dielectric material and the material of plug 60 orthe material of insulative portion 15 or any other such interactionbetween materials in communication with one another. Exemplary highdielectric constant materials employed for layer 50 include, but are notlimited to, Al₂O₃, Ta₂O₅, and barium strontium titanate (BST). Asdepicted, layer 50 does not fill recess 20 and a second capacitorelectrode layer 54 is shown formed and patterned. Such second electrodelayer generally encompasses a material similar to that of material layer36 (FIG. 9A). Advantageously the structure depicted for capacitorstructure 70 is formed by methods analogous to those previouslydescribed with respect to FIGS. 5-10.

[0054] It will be recognized that embodiments of the present inventioninclude methods for forming capacitor structures and removing resistthat provide for the removal of portions of a material withoutpreventing the proper forming of a desired capacitor structure.Embodiments of the present invention can also provide for reducedscratching and smearing of electrode materials by removing portions ofthe resist without the use of particulates within a polishing fluid orin the alternative with very low initial concentrations of particulates.In this manner, little or no scratching or smearing occurs as conductivematerials are exposed. In addition, embodiments of the present inventioncan provide a CMP method that eliminates the use of a photomasking stepfor patterning at least one capacitor electrode. As is known, theremoval of a photomasking step can serve to reduce processing costs andgenerally to increase process yield.

[0055] In compliance with the statute, the invention has been describedin language more or less specific as to structural and methodicalfeatures. It is to be understood, however, that the invention is notlimited to the specific features shown and described, since the meansherein disclosed comprise preferred forms of putting the invention intoeffect. The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

1. A resist removal method, comprising: providing a semiconductorsubstrate; forming a resist-comprising layer over the substrate;contacting the resist-comprising layer with a chemical mechanicalpolishing pad and a polishing fluid, the contacting being effective toremove at least a portion of the resist-comprising layer; and thepolishing fluid having a particle concentration of less than or equal toapproximately 0.1 weight percent during the initiation of thecontacting.
 2. The method of claim 1 where the resist-comprising layercomprises a material selected from the group consisting of a photoresistmaterial, a non-photosensitive resist composition and a polyimidematerial.
 3. The method of claim 1 where the chemical mechanicalpolishing pad comprises a polyurethane material.
 4. The method of claim1 where the polishing fluid comprises a pH of from about 8 to about 12.5. The method of claim 1 where the polishing fluid comprises a pH offrom about 8 to about 12; and comprises one or both of ammonia and TMAH.6. The method of claim 1 where the polishing fluid comprises water. 7.The method of claim 1 where the polishing fluid is chemically unreactivewith the layer.
 8. The method of claim 1 further comprising prior to theforming the resist-comprising layer, forming a conductive material layerover the substrate, the conductive material layer comprising a materialselected from the group consisting of platinum, iridium, ruthenium,tantalum and mixtures thereof.
 9. The method of claim 1 furthercomprising prior to the forming the resist-comprising layer, forming atantalum-containing mass over the substrate; and wherein the polishingremoves the resist-comprising layer selectively relative to thetantalum-containing mass.
 10. The method of claim 9 wherein thetantalum-containing mass comprises one or both of silicon and nitrogenin addition to the tantalum.
 11. The method of claim 1 furthercomprising prior to the forming the resist-comprising layer, forming aconductive material layer over the substrate, the conductive materiallayer comprising platinum.
 12. The method of claim 11 where thecontacting continues until an upper surface of the conductive materiallayer is substantially exposed.
 13. The method of claim 11 where thecontacting further comprises providing a monitoring apparatus fordetermining when an upper surface of the conductive material layer issubstantially exposed.
 14. The method of claim 13 where the monitoringapparatus comprises at least one of a torque monitoring apparatus and anoptical monitoring apparatus.
 15. The method of claim 1 furthercomprising: prior to the forming the resist-comprising layer, forming aconductive material layer over the semiconductor substrate, theconductive material layer comprises a material selected from the groupconsisting of platinum, iridium, ruthenium, tantalum and mixturesthereof; the chemical mechanical polishing pad comprises a polyurethanematerial; the polishing fluid comprises a material chemically unreactivewith the conductive material layer; and the majority of any particlespresent at the initiation comprise silica.
 16. The method of claim 15where the contacting continues until an upper surface of the conductivematerial layer is substantially exposed.
 17. The method of claim 16where the contacting further comprises providing a monitoring apparatusfor determining when the material layer is substantially exposed. 18.The method of claim 1 further comprising, prior to forming theresist-comprising layer: forming at least one recessed region within thesemiconductor substrate; forming a conductive material layer over thesemiconductive substrate and within the at least one recessed region;the forming of the conductive material layer comprising forming theconductive material layer within the at least one recessed region, theconductive material layer partially filling the at least one recessedregion and extending laterally outward from such partially filled regionover an upper surface of the semiconductor substrate; and the forming ofthe resist-comprising layer comprising forming the resist-comprisinglayer within the at least one partially filled recessed region, theresist-comprising layer filling the at least one partially filled regionand extending laterally outward from such filled region over an uppersurface of the conductive material layer.
 19. The method of claim 18where the contacting continues until the upper surface of the conductivematerial layer is substantially exposed.
 20. The method of claim 19further comprising: after the upper surface of the conductive materiallayer is substantially exposed, replacing the polishing fluid with asecond polishing fluid having a composition effective for chemicalmechanical polishing the conductive material layer; and contacting theconductive material layer with the chemical mechanical polishing pad andthe second polishing fluid, the contacting continuing until the uppersurface of the semiconductor substrate is substantially exposed.
 21. Themethod of claim 20 where the conductive material layer comprisestantalum and one or both of silicon and nitrogen, and wherein the secondpolishing fluid comprises T605™, available from Hitachi, together withfrom about 0.1 weight % to about 0.5 weight % H₂O₂.
 22. The method ofclaim 18 where the semiconductor substrate comprises a semiconductiveportion and an insulative portion and where the at least one recessedregion is formed within the insulative portion.
 23. The method of claim18 where the at least one recessed region comprises a region for forminga capacitor, and where the conductive material layer comprises acapacitor electrode.
 24. The method of claim 18 where forming theresist-comprising layer comprises: applying a photoresist material overthe conductive material layer and into the at least one recessed regionto form a photoresist layer; and hard baking the resist layer.
 25. Themethod of claim 18 where the conductive material layer comprises aconductive barrier material layer.
 26. The method of claim 25 where theconductive barrier material layer comprises tantalum silicon nitrideand/or tantalum nitride.
 27. The method of claim 18 where the materiallayer comprises tantalum silicon nitride and/or tantalum nitride.
 28. Amethod for forming a capacitor structure comprising: forming a recesswithin a semiconductor substrate; forming a layer of conductive materialover the semiconductor substrate, the layer lining a bottom andsidewalls of the recess to partially fill the recess and extendinglaterally outward from the partially filled recess over an upper surfaceof the semiconductor substrate; filling the partially filled recess witha resist material, the resist material extending laterally outward fromthe recess as a resist material layer over an upper surface of theconductive material; contacting the resist material layer with achemical mechanical polishing pad and a polishing fluid, the contactingbeing effective to remove at least a portion of the resist materiallayer, the polishing fluid comprising a concentration of particles,other than particles generated by polishing of the resist, of less thanor equal to 0.1 weight percent; and stopping the contacting whensubstantially all of the layer of conductive material disposed over theupper surface of the semiconductor substrate is exposed.
 29. The methodof claim 28 where the concentration of particles in the polishing fluid,other than particles generated by polishing of the resist, is about 0weight percent.
 30. The method of claim 28 where the resist materialcomprises an organic polymer material selected from the group consistingof a photoresist material, a non-photosensitive photoresist compositionand a polyimide material.
 31. The method of claim 28 where the chemicalmechanical polishing pad comprises a polyurethane material.
 32. Themethod of claim 28 where the polishing fluid comprises water.
 33. Themethod of claim 28 where the polishing fluid comprises water and one orboth of ammonia and TMAH.
 34. The method of claim 28 where the chemicalmechanical polishing pad comprises a polyurethane material, thepolishing fluid comprises water and the particles, if any are present,comprise silica.
 35. The method of claim 28 further comprising hardbaking the layer of resist material prior to the contacting.
 36. Themethod of claim 28 further comprising: after the upper surface of thelayer of conductive material is substantially exposed, replacing thepolishing fluid with another polishing fluid having a compositioneffective for chemical mechanical polishing the layer of conductivematerial; and contacting the layer of conductive material with thechemical mechanical polishing pad and the other polishing fluid, thecontacting continuing until the upper surface of the semiconductorsubstrate is substantially exposed.
 37. The method of claim 36 where thesemiconductor substrate comprises a semiconductive portion and aninsulative portion and where the at least one recessed region is formedwithin the insulative portion.
 38. The method of claim 37 where theexposed upper surface of the semiconductor substrate is an upper surfaceof the insulative portion.
 39. The method of claim 36 where the at leastone recessed region comprises a region for forming a capacitor, andwhere the layer of conductive material comprises a capacitor electrode.40. The method of claim 36 where forming the resist layer comprises:applying a resist material over the layer of conductive material, intoand filling the at least one recessed region effective to form theresist layer; and hard baking the resist layer.
 41. The method of claim28 where the layer of conductive material comprises platinum.
 42. Themethod of claim 28 where the layer of conductive material comprisestantalum.
 43. The method of claim 28 where the layer of conductivematerial comprises a material selected from the group consisting ofplatinum, iridium, ruthenium, tantalum and mixtures thereof.
 44. Themethod of claim 28 where the layer of conductive material comprises alayer of conductive barrier material.
 45. The method of claim 44 wherethe layer of conductive barrier material comprises tantalum siliconnitride and/or tantalum nitride.
 46. The method of claim 28 where thelayer of conductive material comprises tantalum silicon nitride and/ortantalum nitride.
 47. A method for forming a capacitor structurecomprising: forming a recess within a semiconductor substrate, therecess having a bottom and sidewalls; depositing a layer of conductivematerial over the bottom and sidewalls of the recess and extendinglaterally outward from recess over the semiconductor substrate adjacentthe recess, the layer of conductive material forming a partially filledrecess; filling the partially filled recess with an organic material,the organic material extending laterally outward from the filled recessforming an organic material layer over the conductive material layeradjacent the recess; first removing the organic material layer from overthe conductive material layer adjacent the recess with a first polishingprocess utilizing a first polishing liquid; second removing theconductive material layer adjacent the recess with a second polishingprocess utilizing a second polishing liquid, the second polishing liquidbeing different than the first polishing liquid; and third removing theorganic material from within the recess.
 48. The method of claim 47where the layer of conductive material comprises a material selectedfrom the group consisting of platinum, iridium, ruthenium, tantalum andmixtures thereof.
 49. The method of claim 47 where the layer ofconductive material comprises a layer of conductive barrier material.50. The method of claim 49 where the layer of conductive barriermaterial comprises tantalum silicon nitride and/or tantalum nitride. 51.The method of claim 47 where the organic material comprises a materialselected from the group consisting of a photoresist material, anon-photosensitive photoresist composition and a polyimide material. 52.The method of claim 47 where the first polishing process comprisescontacting the organic material layer with a chemical mechanicalpolishing pad and the first polishing liquid, the contacting beingeffective to remove at least a portion of the organic material layerover the conductive material layer adjacent the recess.
 53. The methodof claim 47 where the second process comprises contacting the conductivematerial layer with the chemical mechanical polishing pad and the secondpolishing liquid, the contacting being effective to remove at least aportion of the conductive material layer adjacent the recess.